Lipophilic Toxins in Wild Bivalves from the Southern Gulf of California, Mexico.

Ignacio Leyva-Valencia,Christine Band-Schmidt,Jesús Hernández-Castro,Erick Núñez-Vázquez,Francisco Hernández-Sandoval,José Bustillos-Guzmán,Andrew Turner,David López-Cortés,Alison O’Neill

doi:10.3390/md19020099

Abstract

Most of the shellfish fisheries of Mexico occur in the Gulf of California. In this region, known for its high primary productivity, blooms of diatoms and dinoflagellates are common, occurring mainly during upwelling events. Dinoflagellates that produce lipophilic toxins are present, where some outbreaks related to okadaic acid and dinophisystoxins have been recorded. From January 2015 to November 2017 samples of three species of wild bivalve mollusks were collected monthly in five sites in the southern region of Bahía de La Paz. Pooled tissue extracts were analyzed using LC-MS/MS to detect lipophilic toxins. Eighteen analogs of seven toxin groups, including cyclic imines were identified, fortunately individual toxins did not exceed regulatory levels and also the total toxin concentration for each bivalve species was lower than the maximum permitted level for human consumption. Interspecific differences in toxin number and concentration were observed in three species of bivalves even when the samples were collected at the same site. Okadaic acid was detected in low concentrations, while yessotoxins and gymnodimines had the highest concentrations in bivalve tissues. Although in low quantities, the presence of cyclic imines and other lipophilic toxins in bivalves from the southern Gulf of California was constant.

Highlights

The Gulf of California (GuC) has been recognized for supporting extraordinary biological diversity, exceptionally primary high productivity and large populations of marine taxa of vertebrates and invertebrates [1]
The mollusk fisheries from the Gulf of California contribute to nearly 90% of the total production of Mexico [2]
The goal of this study was to determine the lipophilic toxins (LT) occurrence in three bivalve species used for human consumption in Bahía de La Paz, southern GuC, Mexico, to help mitigate against human health threats and to provide useful information for risk assessment of the management processes by future sanitary certifications

Summary

Introduction

The Gulf of California (GuC) has been recognized for supporting extraordinary biological diversity, exceptionally primary high productivity and large populations of marine taxa of vertebrates and invertebrates [1]. GuC, Panopea globosa (geoduck clam) is an important exportation product for the Asian market, while in southern GuC, Megapitaria squalida (chocolate clam), Dosinia ponderosa (white clam), Atrina maura (pen shell) and other bivalves, are important components of the regional gastronomic culture. Most of these species are harvested from wild populations, where their growth is sustained by feeding on the natural phytoplankton community. They can accumulate toxins produced by diatoms and dinoflagellates, even without an evident harmful algal bloom. Bivalves are the first vector of toxins towards humans

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Methods

Results